Once upon a time, it was fairly common for laptops to have unique docking stations that added capabilities like multimedia or networking functions. Those days are mostly past, but in recent years we've seen the emergence of external GPU boxes. Like the docking stations of yore, these self-powered boxes are large, heavy, and intended to occupy a permanent spot on a desk. There's no reason you couldn't bring along a Sonnet Technologies eGFX Breakaway Puck, though. These little boxes pack a Radeon RX 560 or RX 570 into a one-liter package.
The graphics chips in question are the mobile versions. The boxes come with 4 GB of GDDR5 memory connected to their Radeon GPUs. The Breakaway Pucks can drive their respective graphics chips full-bore while sending up to 45W of power to the TB3-connected laptop. Either model can run four monitors in up to 3840x2160 resolution at 60 Hz using a trio of DisplayPort 1.4 connections and a single HDMI 2.0 port.
The Pucks themselves are positively petite. Both models are the same size: 6" wide, 5" deep, and 2" tall (or 15.2 cm x 12.7 cm x 5.1 cm). They're so small that they can be attached to a monitor's VESA mount using an optional bracket. That would seem to miss the point of a portable plug-in performance upgrade, though. The RX 560 model takes a 160W power adapter and the RX 570 model uses a 220W brick. Thankfully, Sonnet has skipped the common flimsy barrel-plug design for a more durable DIN connector.
Sonnet claims that you can plug the RX 560 model into an ultrabook with a Core i7-7600U and whip out nearly 100 FPS on average in Quake Champions with "Ultra" settings. The company also claims that with the RX 570 model, a similar machine could average 120 FPS in Doom on "High" quality. Those are heady claims for an eGPU, although we must stress that the company didn't specify what resolution it used for these tests. Regular TR readers will also be wary of simple average-FPS measurements.
The eGFX Breakaway Pucks are already up for sale at Amazon. The model with the Radeon RX 560 (GPU-RX560-TB3) will run you $449. Its big brother with a Radeon RX 570 (GPU-RX570-TB3) will set you back $599. The "PuckCuff" VESA mounting bracket will be $59 and can be ordered from Sonnet's website. Those prices might seem steep, but miniaturization doesn't come cheap.